In an CMOS static random access memories (SRAMs) it has become common to use a differential amplifier. An example of such a sense amplifier is described in U.S. Pat. No. 4,644,196, Flannagan. One of the characteristics of a differential amplifier is a current source coupled to the sources of a pair of input insulated gate field effect transistors (IGFETs) which receive a pair of differential signals. In general it is considered ideal for the current through the current source to remain constant during amplification of the differential signal. In a CMOS differential amplifier, the current source is normally an IGFET which is enabled by a clock signal. An IGFET acts more like an ideal current source if it is in saturation as opposed to being in its triode region of operation. In order for the current source IGFET to be in saturation its gate to source voltage cannot exceed its threshold voltage by more than its drain to source voltage. As in the case of the above cited Flannagan patent, the current source IGFET generally receives a clock signal which is at or near the power supply voltage. Consequently, the gate to source voltage is at or near the power supply voltage whereas the drain to source voltage is much lower. The threshold voltage is normally less than a volt so that the gate to source voltage easily exceeds the threshold voltage by more than the magnitude of the drain to source voltage. One approach that has been used to cause the current source IGFET to be in saturation is to generate a reference voltage for application to the gate of the current source IGFET. The reference voltage is chosen to ensure that the current source IGFET is in saturation. This solution has some disadvantages which tradeoff with those associated with the approach which uses a standard clock signal. The reference voltage must be generated by a reference circuit which has a current drain associated with it. Additionally, the sense amplifier must have the ability to be tri-stated which may result in a clock signal additional to the reference voltage being required by the sense amplifier. The reference voltage must also be clocked at relatively high speed, which limits how low the current of the reference voltage generator can be.